The invention relates to a malfunction reporting system for a vehicle.
Conventionally, malfunctions in a vehicle are indicated by a symbol in a display. To implement this function, a central check-control module is frequently provided in vehicles, and is connected with different electrical control units (which control respective vehicle systems) by way of a data bus. In some cases, several so-called bus identifiers are assigned to each control unit; and status bits containing information regarding operation of the associated vehicle system are transmitted from the control units to the check-control module, and evaluated there. If necessary, the status bits are linked with additional data. When certain conditions are present, a defect report is emitted in the indicating device in the vehicle, for example, in the instrument cluster.
Low flexibility is a disadvantage of this system, because the check-control module must recognize all status messages. Furthermore, the conditions under which defect reports should be indicated also have to be filed in the check-control module. For this reason, changes in the control units always also cause changes in the check-control module itself. In addition, for communication by way of a data bus, in some cases, several bus identifiers are required for the different control units, which increases the complexity of the overall system. In this respect, the required computing speed in the check-control module rises proportionately with the number of required reports. In addition, the number of available bus identifiers in the bus systems is limited so that, when multiple complex electrical control units are used, a limit is reached with respect to the reports which can be indicated.
Furthermore, heretofore only illuminated symbols have generally been shown in an indicating device for indicating a defect. In the case of symbols that are activated infrequently, a driver must often consult the operating instructions to learn the meaning of the symbol alone (that is, without any explanation).
It is an object of the present invention to provide a flexible defect reporting system for a vehicle which can accommodate the increasing number of reports in future vehicles.
This and other objects and advantages are achieved by the defect reporting system according to the invention, in which the control units are configured to independently evaluate reporting conditions, and to issue a corresponding report to a check-control module when defined failure conditions exist. That is, in contrast to conventional systems, in which only status bits are transmitted to the check-control module describing only the status and various vehicle operating conditions, according to the invention the control unit itself independently evaluates the reports submitted to it and, if defined conditions are present (which must of course therefore be available to the respective control unit), it formulates a corresponding report to the check-control module.
Furthermore, the check-control module has access to a table in which, for each report from a control unit, at least one unit of information is filed, which must then be shown via the indicating device. The check-control module reads from the table the information assigned to the transmitted report, and shows this table by means of the indicating device. A combination indicating device may be used, which preferably also comprises a display. Different symbols and text information can be shown in the display. In addition, it is also possible to control different indicator lights in the combination indicating device, depending on the defect.
Because of the checking of the reporting conditions in the control units themselves, when the data are transmitted by way of a data bus, it is not necessary to use several bus identifiers. Bus identifiers are essentially data which describe the type of information being transmitted via the data bus. In the case of the present invention, it would, for example, be possible to transmit all defects in a certain data format, so that only one bus identifier would then be required. As soon as a report with the bus identifier for a defect report is present on the bus, the check-control module will know that this report contains defect information that has to be processed. Naturally, several bus identifiers for different groups of reports may also be selected.
The respective data formats then each contain one defect report part which comprises a statement which corresponds to the defect detected by a control unit on the basis of the presence of particular conditions.
The report from a control unit therefore preferably comprises the bus identifier and report information. This approach permits the use of the defect reporting system according to the invention when multiple complex electronic control units are operated.
By using a table, in which essentially an assignment of reports originating from a control unit and assigned information is present, it becomes unnecessary to exchange the check-control module or to have to reprogram it to modify its method of operation, when the control units or the defect messages in the control units are changed. Rather, it is sufficient to exchange the information filed in the table (for example, by flash programming) and to correspondingly adapt this information when the system is changed.
Such an adaptation can be performed in a simple manner, first preparing the table by means of a data bank. From this data bank, a source code data file and therefrom a machine-readable data file can be formed, which is programmed into a memory containing the table.
A separate memory can be used for the table, so that when the table must be changed, a new table needs only be read into the memory.
Alternatively, the program part, provided for the operation of the check-control module, and the data part containing the information of the table, may also be constructed as an integrated unit. In this case, the two program parts should be prepared jointly, and newly read into the memory.
The memory may be constructed as a part of the check-control module itself; or the check-control module and the memory may be jointly integrated in an instrument cluster. Other alternatives are of course possible.
For each report, the table can keep on file a plurality of information in the form of texts, graphic information, indicator light activations and/or other reporting action.
By means of the defect reporting system according to the invention, and in particular the self-evaluating control units and the separately filed table, an extremely flexible system is created.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.